Amenorrhea: when not seeing red is a red flag

Have you or someone you know ever lost a regular menstrual cycle, maybe while on a diet or playing an intense sport? Although it has become very normalized in our society, amenorrhea, or lack of a regular menstrual cycle, is not normal, and actually indicative of a health concern. A woman’s menstrual cycle reflects overall health status and can be thought of as a fifth vital sign.


One of the types of amenorrhea, called functional hypothalamic amenorrhea (FHA), is caused by significant weight loss or low energy availability, psychological stress, or intense exercise (or a combination).

Why does it happen?

Inadequate energy availability (from low calorie intake) and high levels of stress have effects on hormones—cortisol increases and gonadotropin-releasing hormone (hint: the one responsible for initiating your period) decreases. This ultimately causes a deficiency in estrogen.

Low estrogen disrupts regular menstrual function, which has effects on puberty and fertility. It also may impair cardiovascular function and cause decreased bone mineral density and even bone loss.

Estrogen is bone-protective! It stimulates bone formation and inhibits bone breakdown. Without enough estrogen, bone formation is suppressed, and bone resorption is stimulated.

It’s estimated that for every year without a menstrual cycle, females can lose more than 2% of their bone density. Women with FHA may be missing out on critical times of bone formation, which may cause irreversible damage on bones and lead to a higher risk of osteoporosis.

Who is at risk?

FHA occurs in women with low body weight, low percentage of body fat, low calorie or fat intake, strenuous exercise, and high levels of stress. Female athletes and women with eating disorders have a disproportionately high prevalence—66-84% of women with anorexia nervosa experience amenorrhea, and the actual number may be even higher.

Women need adequate energy for menstrual function – without adequate energy, bodies will prioritize life-sustaining functions (like your heart beating), and processes like bone formation or reproduction will be put aside.


The underlying issue must be determined to inform treatment—if an eating disorder is present, it requires treatment. Treatment for FHA will usually involve a multidisciplinary approach: nutrition intervention (to restore adequate intake), lifestyle management (exercise and stress reduction), and hormone replacement and leptin therapy may also be considered. Nutrition management will include ensuring adequate calorie, fat, and carbohydrate intake, as well as making up for increased metabolic needs; weight restoration may be necessary; and treatment must be individualized—there is no standard calorie or fat prescription to recommend.

Individuals with eating disorders or disordered eating, and athletes should be screened for amenorrhea. A multidisciplinary team should help the individual address all of the present issues (including coming up with an individualized meal plan). It’s important to note that oral birth control pills may induce bleeding, but they will not treat the underlying issue(s). All women should be educated on the importance of maintaining appropriate calorie intake and body weight, and risks of not doing so -like irreversible bone loss.

The Registered Dietitians at Nourish Family Nutrition provide treatment for amenorrhea and eating disorders. Book an appointment at www.nourishfamily.com or by calling 410-370-0415.

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